Tow bar having a single moving part for operatively accommodating pitch and roll movements between a towing vehicle and a towed vehicle

ABSTRACT

A tow bar for connecting a towed vehicle to a towing vehicle, the tow bar comprising a towing vehicle connection mechanism connected to the towing vehicle; a towed vehicle connection mechanism connected to the towed vehicle; and an interconnecting mechanism connecting the towing vehicle connection mechanism to the towed vehicle connection mechanism. The interconnecting mechanism defines an interconnection central point and an interconnection vertical axis spaced rearwardly from the interconnection central point. The interconnecting mechanism is structured to accommodate substantially all pitch and roll movements between the towing and towed vehicles at and about the interconnection central point, and to accommodate substantially all yaw movements between the towing and towed vehicles at and about the interconnection vertical axis.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 10/840,033 filed May 7, 2004, now U.S. Pat. No. 6,991,247. U.S.application Ser. No. 10/910,543 filed Aug. 4, 2004, now U.S. Pat. No.7,032,919 is a continuation-in-part application of U.S. application Ser.No. 10/840,033 filed May 7, 2004, now U.S. Pat. No. 6,991,247.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to accessories for vehicles and, morespecifically without limitation, to an apparatus for towing a vehiclebehind another vehicle.

2. Discussion of the Related Art

There is an ever-increasing need to be able to tow a driverless vehiclebehind another vehicle. One common situation where this need arisesoccurs for persons traveling in a motorhome. Most motorhomes are toolarge to conveniently visit many sites of interest near an overnightstop-over. As a result, many motorhome users tow a small automobilebehind their motorhome so the small automobile can be used for localtransportation after the motorhome has been parked.

Various devices are used for towing a vehicle, sometimes referred toherein as a towed vehicle, behind another vehicle, sometimes referred toherein as a towing vehicle. One such device is commonly referred to as adolly. A dolly is generally a two-wheeled vehicle with a tongue thatconnects to a trailer hitch, such as a ball-type hitch, fixedlyconnected to the rear of the towing vehicle. To tow a vehicle with thedolly, the vehicle to be towed is driven up behind the dolly and, by useof a small ramp-like arrangement, onto the dolly so the front wheels ofthe towed vehicle are supported by the dolly. The front wheels are thensecurely clamped to the dolly, such as with chains and turnbuckles, orother suitable clamping arrangement. When the towing vehicle is drivenforward, the dolly follows the towing vehicle by virtue of theconnection between the dolly and the trailer hitch of the towingvehicle, and the towed vehicle follows the dolly by virtue of the frontwheels of the towed vehicle being supported by and clamped to the dolly.

A major drawback with the use of a dolly occurs when it becomesnecessary to back up the tandem assemblage consisting of the towingvehicle connected to the dolly connected to the towed vehicle. Thetowing vehicle has a first set of wheels mounted on a front axle and asecond set of wheels mounted on a rear axle. The dolly has a third setof wheels mounted on an axle, which constitutes a third axle spacedrearwardly from the two axles of the towing vehicle. The towed vehiclehas a fourth set of wheels mounted on its rear axle, which constitutes afourth axle spaced further rearwardly from the two axles of the towingvehicle and from the axle of the dolly. To operatively andsimultaneously manipulate those four axles, each having a pair of wheelsin contact with the ground therebeneath, such as when the tandemassemblage needs to be backed up, is a very difficult task even for anexperienced driver. Of course, the towed vehicle could be unchained andunloaded from the dolly and individually driven out of the way, thedolly disconnected from the towing vehicle and physically placed out ofthe way, and the towing vehicle could then be backed up as needed.Obviously, such extra time and effort to simply back up the towingvehicle would be bothersome and aggravating, to say the least.

Another device that is commonly used to tow a driverless vehicle behindanother vehicle is a tow bar. Tow bars are readily available in manydifferent forms. Tow bars usually have either a socket at the forwardend thereof for connecting to a ball-type hitch fixedly connected to therear of the towing vehicle, or a square-shaped forwardly-extending tubefor connecting to a conventional receiver hitch fixedly connected to therear of the towing vehicle. In addition, tow bars usually have twotowbar arms extending rearwardly to connect to the front end of a towedvehicle to thereby form a triangularly-shaped arrangement between thetwo towbar arms and the front end of the towed vehicle.

One such tow bar is disclosed in U.S. Pat. No. RE35,482 issued Mar. 25,1997 to Andrew B. Johnson. The Johnson tow bar includes aforwardly-extending hitch tube for connecting to a conventional receiverhitch of a towing vehicle. A roll axis is defined by a fore-to-aftoriented pin pivotally connecting a rearwardly-directed yoke to a plateattached to the hitch tube. A pivot block, spaced rearwardly from thefore-to-aft oriented pin, has a horizontally-oriented throughboreoriented perpendicularly to the fore-to-aft oriented pin. A pitch axisis defined by a pin passing through the horizontally-orientedthroughbore of the pivot block, which pivotally connects the pivot blockto the yoke. The pivot block also has a vertical-oriented throughborespaced rearwardly from the horizontal-oriented throughbore of the pivotblock. A yaw axis is defined by a bolt passing through thevertically-oriented throughbore of the pivot block, which pivotallyconnects the pivot block to the forward ends of a pair of towbar arms.The rear end of each towbar arm includes a pivot arm for swinging aroundrearwardly to connect to a towed vehicle, or for swinging aroundforwardly to lock alongside the respective towbar arm for storagepurposes. The Johnson tow bar can be pivoted upwardly about thehorizontally-oriented pin through the pivot block for storage on therear of the towing vehicle.

One problem with the Johnson tow bar is the plurality of moving partsthereof. Each of those moving parts are operatively subjected tosubstantial wear and abuse and therefore failure during use, namely, thefore-to-aft oriented pin, which is subjected to constant relativemovement between the yoke and the plate attached to the hitch tube; thehorizontally-oriented pin, which is subjected to constant relativemovement between the pivot block and the yoke; and thevertically-oriented pin, which is subjected to constant relativemovement between the towbar arms and the pivot block.

Another problem with the Johnson tow bar is the spaced-apartconfiguration of the various articulation axes thereof; morespecifically, accommodation of roll, pitch and yaw movements between thetowing vehicle and the towed vehicle are confined to separately-definedand spaced-apart axes: the fore-to-aft oriented pin through therearwardly-directed yoke for roll movements, the horizontally-orientedpin through the rearwardly-directed yoke and the pivot block for pitchmovements, and the vertically-oriented pin through the pivot block andthe forward ends of the towbar arms for yaw movements. The cause forconcern in regard to the spaced-apart structuring of the articulationaxes of the Johnson tow bar arises from moments that are operativelycreated in the tow bar, which moments can only be countered internallywithin the tow bar by pitting one part of the tow bar against anotherpart of the tow bar. Moments which must be countered internally withinthe tow bar increase wear and tear of those tow bar parts and, as aresult, decrease the meantime before failure of the tow bar. Morespecifically, in the structure of the Johnson tow bar, the yaw axis isspaced rearwardly from the pitch axis which, in turn, is spacedrearwardly from the roll axis which, in turn, is spaced vertically fromthe fore-to-aft axis of the receiver hitch.

Various force components are imposed by the towed vehicle on thevertical pin through the pivot block, the yaw axis, by virtue of thetowed vehicle being connected to the vertically-oriented pin by thetowbar arms. For example, in any turning situation where the towedvehicle is not lined up rearwardly from the towing vehicle, the towedvehicle causes the towbar arms to impose a horizontal, transverse forcecomponent on the vertically-oriented pin through the pivot block.Although the yaw axis at that vertically-oriented pin of the Johnson towbar can accommodate the transverse force components imposed thereon bythe towed vehicle and the towbar arms, those transverse force componentsare, in turn, imposed on the vertically-oriented pin through the pivotblock, and there is no other structure spaced forwardly therefrom thatcan provide another yaw axis to accommodate the transverse forcecomponents imposed on the vertically-oriented pin. The same reasoningapplies whether the transverse force components are to the left or tothe right—in other words, all turning situations.

Similarly, in any operative situation where the towing vehicle enters anupgrade or a downgrade before the towed vehicle enters that grade changeor the wheels of the towing vehicle are momentarily supported on a planethat is at a different elevation than the plane supporting the wheels ofthe towed vehicle, the towed vehicle causes the towbar arms to impose avertical force component on the vertically-oriented pin through thepivot block, which vertical force component is transferred to andaccommodated by the pitch axis at the horizontally-oriented pin throughthe pivot block. However, there is no other structure spaced forwardlyfrom the horizontally-oriented pin through the pivot block that canprovide another pitch axis to accommodate the vertical force componentsimposed on the horizontally-oriented pin through the pivot block. Thesame reasoning applies whether the vertical force components areupwardly or downwardly—in other words, all pitch situations.

Finally, at all operative times, the towed vehicle causes the towbararms to impose fore-to-aft force components or aft-to-fore forcecomponents on the vertically-oriented pin through the pivot block, suchas when the towing vehicle and towed vehicle are speeding up, slowingdown, going up or down an incline, or just cruising. The fact that thefore-to-aft oriented pin through the rearwardly-directed yoke is notaligned with the fore-to-aft oriented axis of the receiver hitch of thetowing vehicle, such constantly varying fore-to-aft force componentsimposed by the towed vehicle and the towbar arms, create moments thatmust be countered internally by the plate attached to the hitch tube andby the connection of the fore-to-aft oriented pin to that plate. Themagnitude of the lever arm of that moment would be the spacing betweenthe orifice through the rearwardly-directed yoke for the fore-to-aftoriented pin and the receiver hitch of the towing vehicle.

In addition to the moments created in the fore-to-aft pin and the plateconnecting that pin to the hitch tube by fore-to-aft force components,other moments which the Johnson tow bar must internally oppose fromforce components imposed on the tow bar by the towed vehicle and thetowbar arms can be described as follows:

-   -   (a) transverse force components create (i) moments in the pivot        block with the magnitude of the lever arm thereof being        determined by the spacing between the vertically-oriented and        horizontally-oriented pins through the pivot block, (ii) moments        in the rearwardly-directed yoke with the magnitude of the lever        arm thereof being determined by the spacing between the        vertically-oriented pin through the pivot block and the orifice        through the rearwardly-directed yoke for the fore-to-aft        oriented pin, and (iii) moments in the fore-to-aft oriented pin        and the plate attached to the hitch tube with the magnitude of        the lever arm thereof being determined by the spacing between        the vertically-oriented pin through the pivot block and the        hitch tube; and    -   (b) vertical force components create (i) moments in the        rearwardly-directed yoke with the magnitude of the lever arm        thereof being determined by the spacing between the        horizontally-oriented pin through the pivot block and the        orifice through the rearwardly-directed yoke for the fore-to-aft        oriented pin, and (ii) moments in the fore-to-aft oriented pin        and the plate attached to the hitch tube with the magnitude of        the lever arm thereof being determined by the spacing between        the horizontally-oriented pin through the pivot block and the        hitch tube.

Another Shortcoming of the Johnson Tow Bar

Of course, the various parts of the Johnson tow bar could be constructedmuch more massively to enhance the strength thereof in an attempt tomore capably withstand the moments created internally within the tow bardue to the spaced-apart structuring of the yaw, pitch and roll axes.Unfortunately, such over-construction would defeat the ability toprovide a relatively light-weight, easily manageable tow bar having thestructure disclosed by Johnson.

Another such tow bar is disclosed in U.S. Pat. No. 5,765,851 issued Jun.16, 1998 to Richard A. Parent. The Parent tow bar includes aforwardly-extending hitch member for connecting to a conventionalreceiver hitch fixedly connected to the rear of a towing vehicle. Apitch axis is defined by a horizontal transversely-oriented bolt, whichconnects a forwardly-directed yoke to the hitch member. A roll axis isdefined by a fore-to-aft oriented bolt, which connects theforwardly-extending yoke to a rearwardly-extending yoke. A yaw axis isdefined by a vertically-oriented bolt, which connects therearwardly-directed yoke to the forward ends of a pair of towbar arms.The rear end of each towbar arm is connected to a towed vehicle.

As with the Johnson tow bar, one problem with the Parent tow bar is theplurality of moving parts thereof. Each of those moving parts isoperatively subjected to substantial wear and abuse and thereforefailure during use, namely, the horizontal transversely-oriented bolt,which is subjected to constant relative movement between theforwardly-directed yoke and the hitch member; the fore-to-aft orientedbolt, which is subjected to constant relative movement between theforwardly-directed yoke and the rearwardly-directed yoke; and thevertically-oriented bolt which is subjected to constant relativemovement between the rearwardly-directed yoke and the towbar arms.

Also as with the Johnson tow bar, another problem with the Parent towbar is the spaced-apart configuration of the various articulation axesthereof; more specifically, accommodation of pitch, roll and yawmovements between the towing vehicle and the towed vehicle are confinedto separately-defined and spaced-apart axes: the horizontally-orientedpin through the hitch member and the forwardly-directed yoke for pitchmovements, the fore-to-aft oriented pin through the forwardly-directedand rearwardly-directed yokes for roll movements, and thevertically-oriented pin through the rearwardly-directed yoke and theforward ends of the towbar arms for yaw movements.

As hereinbefore explained, the cause for concern in regard to thespaced-apart structuring of the articulation axes of the Parent tow bararises from moments that are operatively created in the tow bar, whichmoments can only be countered internally within the tow bar by pittingone part thereof against another part thereof. Again, moments which mustbe countered internally within the tow bar by various parts of the towbar increase wear and tear of those parts and, as a result, decrease themeantime before failure of the tow bar. In the structure of the Parenttow bar, the yaw axis is spaced rearwardly from the roll axis which, inturn, is spaced rearwardly from the pitch axis which, in turn, is spacedrearwardly from the receiver hitch of the towing vehicle.

Various force components are imposed by the towed vehicle on thevertically-oriented bolt through the rearwardly-directed yoke, the yawaxis, by virtue of the towed vehicle being connected to thevertically-oriented bolt by the towbar arms. For example, in any turningsituation, the towed vehicle causes the towbar arms to exert ahorizontal transverse force component on the vertically-oriented boltthrough the rearwardly-directed yoke. Although the yaw axis at thatvertically-oriented pin can accommodate transverse force components ofthe towed vehicle and the towbar arms, those transverse force componentsare imposed on the fore-to-aft oriented bolt through therearwardly-directed and forwardly-directed yokes, and there is no otherstructure spaced forwardly therefrom that can provide another yaw axisto accommodate the transverse force components imposed on thefore-to-aft bolt through the rearwardly-directed and forwardly-directedyokes.

Similarly, in any operative situation where the towing vehicle enters anupgrade or a downgrade before the towed vehicle enters that grade changeor the wheels of the towing vehicle are momentarily supported on a planethat is at a different elevation than the plane supporting the wheels ofthe towed vehicle, the towed vehicle causes the towbar arms to impose avertical force component on the vertically-oriented bolt through therearwardly-directed yoke of the Parent tow bar. Although the pitch axisat the horizontally-oriented bolt through the forwardly-directed yokeand the hitch member can accommodate such vertical force componentsimposed by the towed vehicle and the towbar arms, there is no otherstructure spaced forwardly therefrom that can provide another pitch axisto accommodate the vertical force components imposed on thehorizontally-oriented bolt.

As a result of the foregoing, the moments which the Parent tow bar mustinternally oppose from force components imposed by the towed vehicle andthe towbar arms can be described as follows:

-   -   (a) transverse force components create (i) moments in the        rearwardly-directed yoke with the magnitude of the lever arm        thereof being determined by the spacing between the        vertically-oriented bolt through the rearwardly-directed yoke        and the fore-to-aft oriented bolt through the        rearwardly-directed and forwardly-directed yokes, (ii) moments        in the forwardly-directed yoke with the magnitude of the lever        arm thereof being determined by the spacing between the        vertically-oriented bolt through the rearwardly-directed yoke        and the horizontal pin through the forwardly-directed yoke,        and (iii) moments in the hitch tube with the magnitude of the        lever arm thereof being determined by the spacing between the        vertically-oriented bolt through the rearwardly-directed yoke        and the hitch member; and    -   (b) vertical force components create moments in the hitch member        with the magnitude of the lever arm thereof being determined by        the spacing between the horizontally-oriented bolt through the        forwardly-directed yoke and the hitch member.

Again, the various parts of the Parent tow bar could be constructed muchmore massively to enhance the strength thereof in an attempt to morecapably withstand the moments created internally within that tow bar dueto the spaced-apart structuring of the yaw, roll and pitch axes. Andagain, such over-construction would defeat the ability to provide arelatively light-weight, easily manageable tow bar having the structuredisclosed by Parent.

A tow bar that has solved many of the problems of the Johnson and Parenttow bars is disclosed in U.S. Pat. No. 6,502,847 issued Jan. 7, 2003 toJohn Greaves. The Greaves tow bar includes a forwardly-extendinghitching portion for connecting to a conventional receiver hitch fixedlyconnected to the rear of a towing vehicle. The equivalent of pitch, rolland yaw axes are all provided by a hitch ball member mounted in a hitchsocket member with a rearwardly-directed hitch socket central aperture.The hitch ball member comprises two hemispheres, one spaced above theother in the hitch socket member. One of the hemispheres is fixedlyattached to the forward end of one of the towbar arms, whereas the otherhemisphere is fixedly attached to the forward end of the other towbararm. The towbar arms extend rearwardly through the hitch socket centralaperture. The hemispheres rotate relative to each other about avertically-oriented axis when the towbar arms are spread apart to form atriangularly-shaped arrangement with the towed vehicle by use of twospaced-apart plate ball members fixedly connected to the rear ends ofthe towbar arms and connected to the front of the towed vehicle.Unfortunately, such relative rotation between the hemispheres, withinthe hitch socket member with the towbar arms fixedly attached thereto,reduces the remaining available spacing between the towbar arms and theperiphery of the hitch socket central aperture thereby reducing theextent of relative movement available for accommodating pitch and yawmovements between the towing vehicle and the towed vehicle. Althoughspecial slots are provided in the hitch socket central aperture in orderto enhance the movement available for relative yaw movements, a pitchmovement occurring at the same time as a yaw movement that requires useof the special slots would defeat the intended purpose of the specialslots.

An improvement provided by the Greaves tow bar over the Johnson andParent tow bars is the substantial reduction in the number of movingparts that may be subject to failure during use. However, with one ofthe towbar arms being fixedly attached to a first one of the hemispheresand the other towbar arm being fixedly attached to the other hemispherewhich is offset from the first hemisphere, an internal moment isoperatively created between the two hemispheres.

Unfortunately, another drawback of the Greaves tow bar is the failure toprovide a means for conveniently and rotatably storing the tow bar onthe rear of the towing vehicle. Due to the towbar arms being fixedlyconnected to the hemispheres, due to the towbar arms extendingrearwardly through the hitch socket central opening, and due to thelimited ability to rotate the hemispheres thereby preventing the towbararms from being displaced to an upright orientation, such convenient androtatable storability does not appear to be possible without substantialstructural modification to the Greaves tow bar, which is not taught orimplied by the Greaves reference.

What is needed is a tow bar wherein the towbar arms thereof are notfixedly connected to hemispheres; wherein the towbar arms do not extendthrough a rearwardly-facing central opening in a manner that inhibitspitch and yaw movements between a towing vehicle and a towed vehicle;wherein the number of moving parts subject to failure during use isgreatly reduced when a towed vehicle is being towed by a towing vehicle;wherein the connection between the towbar arms does not create a momentbetween the tow bar arms within a hitch socket member; and wherein thetow bar can be conveniently stored on the rear of a towing vehiclewithout having to disconnect the tow bar from the towing vehicle.

PRINCIPAL OBJECTS AND ADVANTAGES OF THE INVENTION

The principal objects and advantages of the present invention include:providing a tow bar having towbar arms that are not fixedly connected tohemispheres; providing such a tow bar wherein the towbar arms do notextend through a rearwardly-facing central opening in a manner thatinhibits yaw and pitch movements between a towing vehicle and a towedvehicle; providing such a tow bar wherein the number of different partsthat may be subject to failure during use is substantially reduced;providing such a tow bar wherein the number of moments createdinternally with the tow bar is substantially reduced; providing such atow bar that can be conveniently stored on the rear of a towing vehiclewithout having to disconnect the tow bar from the towing vehicle; andgenerally providing such a tow bar that is reliable in performance,capable of long lasting life, and particularly well suited for theproposed usages thereof.

Other objects and advantages of this invention will become apparent fromthe following description taken in conjunction with the accompanyingdrawings wherein are set forth, by way of illustration and example,certain embodiments of this invention.

SUMMARY OF THE INVENTION

The improvements of the tow bar of the present invention include atowing vehicle connection mechanism for connecting to a towing vehicle,the towing vehicle connection mechanism including a hitching mechanismstructured and configured to be received by a conventional receiverhitch of the towing vehicle, and defining a fore-to-aft oriented towingvehicle axis that is operatively fixed relative to the towing vehicleand to the towing vehicle connection mechanism. The tow bar of thepresent invention also includes a towed vehicle connection mechanism forconnecting to a towed vehicle, the towed vehicle connection mechanismincluding at least one bracket attached to the towed vehicle, anddefining a horizontal transversely-oriented towed vehicle axis that isoperatively fixed relative to the towed vehicle and to the towed vehicleconnection mechanism. The tow bar of the present invention furtherincludes an interconnecting mechanism connecting the towing vehicleconnection mechanism to the towed vehicle connection mechanism, theinterconnecting mechanism defining an interconnection central point,defining an interconnection vertical axis spaced rearwardly from theinterconnection central point, and including a spherically-shaped ballmember having a radius and a ball member center point; a body memberhaving a main cavity with a main cavity center point and a radius ofcurvature, which is slightly greater than the radius of the ball member;the body member further including an upper body portion with adownwardly-facing, partially hemispherically-shaped upper cavity havinga radius of curvature, which is slightly greater than the radius of theball member, and a center of curvature; a lower body portion with anupwardly-facing, partially hemispherically-shaped lower cavity having aradius of curvature, which is identical to the radius of curvature ofthe upper cavity of the upper body portion, and a center of curvature;and fastening means. Assembly of the upper body portion, the lower bodyportion and the ball member with the fastening means forms the maincavity of the body member wherein the center of curvature of the uppercavity of the upper body portion, the center of curvature of the lowercavity of the lower body portion, and the ball member center point allcoincide with the main cavity center point, rotatively capturing theball member therein. The upper body portion abuts the lower body portionalong a plane that passes through the main cavity center point. The towbar of the present invention also includes a slot cooperatively formedby the upper body portion in conjunction with the lower body portion,the slot having a slot width; a shaft member having a forward endaffixed to the towing vehicle connection mechanism, a rearward endaffixed to the ball member, and a diameter which is slightly smallerthan the slot width, wherein the shaft member extends forwardly from theball member through the slot; a rearwardly-projecting towbar armconnector affixed to the body member, and a pair of towbar arms, eachhaving a forward end and a rear end, wherein the rear ends thereof areoperatively spaced apart and connected to the towed vehicle connectionmechanism, and the forward ends thereof are not spaced apart and aremovably connected to the towbar arm connector to pivot about theinterconnection vertical axis; and a latching mechanism structured andconfigured to secure the interconnecting mechanism in a stowedconfiguration, the latching mechanism comprising a first latching deviceconnected to the towbar arm connector, and a second latching deviceaffixed to the towing vehicle connection mechanism. The body member isrotated about the ball member to displace the slot along the shaftmember to dispose the towbar arm connector in a generally uprightorientation, the first latching device in conjunction with the secondlatching device releasably securing the interconnecting mechanism in thestowed configuration.

A modified embodiment of the improved tow bar of the present inventionincludes a towing vehicle connection mechanism; a towed vehicleconnection mechanism; and an interconnecting mechanism connecting thetowing vehicle connection mechanism to the towed vehicle connectionmechanism. The interconnecting mechanism includes a spherically-shapedball member and a body member comprising a first body portion having arearwardly-facing, partially hemispherically-shaped first cavity with aradius of curvature, which is slightly greater than the radius of theball member, and a center of curvature; a second body portion with aforwardly-facing, partially hemispherically-shaped second cavity with aradius of curvature, which is identical to the radius of curvature ofthe first cavity of the first body portion, and a center of curvature;and a third body portion with a forwardly-facing, partiallyhemispherically-shaped third cavity with a radius of curvature, which isidentical to the radius of curvature of the second cavity of the secondbody portion, and a center of curvature; and fastening means. Assemblyof the first body portion, the second body portion, the third bodyportion and the ball member with the fastening means forms the maincavity of the body member wherein the center of curvature of the firstcavity of the first body portion, the center of curvature of the secondcavity of the second body portion, the center of curvature of the thirdcavity of the third body portion, and the ball member center point allcoincide, rotatively capturing the ball member therein. The modifiedembodiment further includes a slot having a slot width, the slot beingcooperatively formed between the second and third body portions byassembly of the body member; a shaft member having a diameter which isslightly smaller that the slot width, a forward end thereof affixed tothe ball member, and a rearward end thereof extending rearwardly throughthe slot; a towbar arm connector affixed to the shaft member; and a pairof towbar arms, each having a forward end and a rear end, wherein therear ends thereof are operatively spaced apart and connected to thetowed vehicle connection mechanism, and the forward ends thereof are notspaced apart and are movably connected to the towbar arm connector topivot about the interconnection vertical axis; and a latching mechanismstructured and configured to secure the interconnecting mechanism in astowed configuration, the latching mechanism including a first latchingdevice affixed to the ball member and a second latching device affixedto the body member. As the ball member is selectively rotated within thebody member to displace the shaft member along the slot to therebydispose the shaft member in a generally upright orientation, the firstlatching device in conjunction with the second latching devicereleasably secures the interconnecting mechanism in the stowedconfiguration.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a side elevational view of a tow bar having a single movingpart for operatively accommodating pitch and roll movements between atowing vehicle and a towed vehicle, according to the present invention.

FIG. 2 is an enlarged and fragmentary, top plan view of the tow bar ofthe present invention.

FIG. 3 is an enlarged and fragmentary, side elevational view of the towbar of the present invention, showing first and second latching devicesof a latching mechanism thereof.

FIG. 4 is a further enlarged and fragmentary, partially cross-sectionalview of the tow bar of the present invention, showing a body memberthereof rotated sidewise.

FIG. 5 is an enlarged and fragmentary, exploded side elevational view ofa ball member and the body member of the tow bar of the presentinvention.

FIG. 6 is a rear elevational view showing the tow bar of the presentinvention in a stowed configuration.

FIG. 7 is an enlarged side elevational view of a reinforced version ofthe ball member of the tow bar of the present invention.

FIG. 8 is an exploded view of FIG. 7 of the reinforced version of theball member of the tow bar of the present invention.

FIG. 9 is a side elevational view of a modified embodiment of the towbar having a single moving part for operatively accommodating pitch androll movements between a towing vehicle and a towed vehicle, accordingto the present invention.

FIG. 10 is an enlarged and fragmentary, top plan view of the modifiedembodiment of the tow bar of the present invention.

FIG. 11 is an enlarged and fragmentary, partially cross-sectional,exploded side elevational view of the modified embodiment of the tow barof the present invention.

FIG. 12 is an enlarged and fragmentary, partially cross-sectionalexploded top plan view of a reinforced version of a ball member of themodified embodiment of the tow bar of the present invention.

FIG. 13 is a rear elevation view showing the modified embodiment of thetow bar of the present invention in a stowed configuration.

DETAILED DESCRIPTION OF THE INVENTION

As required, embodiments of the present invention are disclosed herein,however, it is to be understood that the disclosed embodiments aremerely exemplary of the invention, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forclaims and as a representative basis for teaching one skilled in the artto variously employ the present invention in virtually any appropriatelydetailed structure.

The reference numeral 10 generally refers to a tow bar for connecting atowed vehicle to a towing vehicle in accordance with the presentinvention, as shown in FIGS. 1 through 8. The present invention 10includes a towing vehicle connection mechanism 13 for connecting the towbar 10 to a towing vehicle 15, the towing vehicle connection mechanism13, upon insertion and securement in a conventional receiver hitch 17 ofthe towing vehicle 15, as indicated by an arrow designated by numeral 19in FIG. 1, operatively defining a fore-to-aft towing vehicle axis 21that is fixed relative to the towing vehicle 15 and to the towingvehicle connection mechanism 13; a towed vehicle connection mechanism 23for connecting the tow bar 10 to a vehicle to be towed by the towingvehicle 15, sometimes referred to herein as the towed vehicle 25, thetowed vehicle connection mechanism 23 operatively defining a horizontaltransversely-oriented towed vehicle axis 27 that is fixed relative tothe towed vehicle 25 and to the towed vehicle connection mechanism 23;and an interconnecting mechanism 33 connecting the towing vehicleconnection mechanism 13 to the towed vehicle connection mechanism 23.

The towing vehicle connection mechanism 13 includes aforwardly-extending hitching mechanism 35 that is structured andconfigured to be received by the conventional receiver hitch 17 fixedlymounted at the rear of the towing vehicle 15.

The towed vehicle connection mechanism 23 includes one or more brackets37 connected to the towed vehicle 25, or other suitable means, such as abaseplate connector as commonly known in the art, or such as thosedisclosed in U.S. Pat. No. 5,224,960 issued Jul. 6, 1993 to Lee H.Duncan and in U.S. Pat. No. 5,356,166 issued Oct. 18, 1994 to Merton K.Hahne et all, both of which disclosures are incorporated herein byreference.

The interconnecting mechanism 33 includes a spherically-shaped member41, having a two-inch diameter for example, sometimes referred to hereinas a ball member 41, which has a radius and a ball member center point43 at the center of curvature of the ball member 41.

The interconnecting mechanism 33 also includes a body member 45. Thebody member 45 includes a main cavity 47 having a main cavity centerpoint 49 located at the center of curvature 49 of the main cavity 47.The radius of curvature of the main cavity 47 is slightly greater thanthe radius of the ball member 41. A preferred embodiment of the presentinvention includes the body member 45 having an upper body portion 53with a downwardly-facing, partially hemispherically-shaped upper cavity55 with a radius of curvature, which is slightly greater than the radiusof the ball member 41, and a center of curvature 57; and a lower bodyportion 63 with an upwardly-facing, partially hemispherically-shapedlower cavity 65 with a radius of curvature, which is identical to theradius of curvature of the upper cavity 55 of the upper body portion 53,and a center of curvature 67.

The main cavity 47 is structured and dimensioned to rotatively capturethe ball member 41 therein, as described herein, such that each of theball member center point 43, the center of curvature 57 of the upperbody portion 53, and the center of curvature 67 of the lower bodyportion 63 coincides with the main cavity center point 49 of the maincavity 47, sometimes referred to herein as the interconnection centralpoint 69.

The interconnecting mechanism 33 also includes fastening means 73, suchas a plurality of cap screws 73 as shown in FIG. 5, to assemble the bodymember 45 from the upper body portion 53 and the lower body portion 63.Assembly of the upper body portion 53, the lower body portion 63 and theball member 41 with the fastening means 73 brings together the upper andlower cavities 55, 65 of the upper and lower body portions 53, 63 tocooperatively form the main cavity 47 for rotatively capturing the ballmember 41 therein. Preferably, after assembly, the upper body portion 53and the lower body portion 63 abuttingly engage each other along a plane75 that passes through the main cavity center point 49 of the maincavity 47 formed by the upper and lower cavities 55, 65.

During assembly, the upper body portion 53 and the lower body portions63 are securely fastened together with the fastening means 73, such asby threading vertically-oriented cap bolts 73 into mated tapped partialbores 79 as indicated in FIG. 5, or other suitable fasteningarrangement.

The interconnecting mechanism 33 also includes a slot 83 having a slotwidth 85 and a shaft member 87 having a forward end 89 and a rearwardend 91. The slot 83 is cooperatively formed during assembly by the upperbody portion 53 in conjunction with the lower body portion 63. The shaftmember 87 has a diameter that is dimensioned slightly smaller than theslot width 85. The forward end 89 of the shaft member 87 is affixed tothe towing vehicle connection mechanism 13 and the rearward end 91 ofthe shaft member 87 is affixed to the ball member 41, with the shaftmember 87 extending forwardly from the ball member 41 through the slot83.

The interconnecting mechanism 33 also includes a rearwardly-projectingtowbar arm connector 95 affixed to the body member 45, and at least one,preferably two, towbar arms 97, 99. Each towbar arm 97, 99 has a forwardend 101 and a rear end 103. The rear ends 103 of the towbar arms 97, 99are operatively spaced apart from each other for connection to the towedvehicle connection mechanism 23. The forward ends 101 of the towbar arms97, 99 are not spaced apart from each other and are movably connected tothe towbar arm connector 95 to pivot about an interconnection verticalaxis 107.

The interconnection vertical axis 107 is provided by a pin 109 through avertically-oriented throughbore 111 in the towbar arm connector 95, asshown in FIG. 5, or other suitable arrangement. The towbar arms 97, 99are independently movable relative to each other for purposes ofconnecting the towbar arms 97, 99 to the towed vehicle connectionmechanism 23. Operatively, however, the towbar arms 97, 99 move inunison to accommodate yaw movements between the towing vehicle 15 andthe towed vehicle 25.

The interconnecting mechanism 33 also includes a latching mechanism 117which is structured and configured to secure the interconnectingmechanism 33 in a stowed configuration 119, as shown in FIG. 6. Thelatching mechanism 117 includes a first latching device 121 connected tothe towbar arm connector 95, and a second latching device 123 affixed tothe towing vehicle connection mechanism 13.

The latching mechanism 117 is structured and configured wherein the bodymember 45 can be rotated about the ball member 41 to displace the slot83 along the shaft member 87 to thereby dispose the towbar arm connector95 in a generally upright configuration. Then, by tilting the towbar armconnector 95 to the right or left, the first latching device 121 engagesone of the ends 125 of an oblong notch 127 of the second latching device123, the first latching device 121 in conjunction with the secondlatching device 123 thereby releasably securing the interconnectionmechanism 33 in the stowed configuration 119 on the back of the towingvehicle 15. If necessary, the width of the slot 83 may be enlarged nearan upper end thereof in order to permit the first latching device 121 tofully engage an appropriate end 125 of the oblong notch 127 of thesecond latching device 123.

It should now be obvious from the disclosure herein that theinterconnecting mechanism 33 is configured and structured to accommodatesubstantially all pitch and roll movements, including any and allcombinations thereof, between the towing vehicle axis 21 and the towedvehicle axis 27, at and about the interconnection central point 69. Theinterconnecting mechanism 33 is further configured and structured toaccommodate substantially all yaw movements, between the towing vehicleaxis 21 and the towed vehicle axis 27, at and about the interconnectionvertical axis 107 in the towbar arm connector 95.

It should be noted that the pitch and roll movements between thefore-to-aft towing vehicle axis 21 and the horizontaltransversely-oriented towed vehicle axis 27 while the towed vehicle 25is being towed by the towing vehicle 15 are effectively accommodated bya single moving part: the ball member 41 within the body member 45; inother words at the coincidence of the main cavity center point 49 andthe ball member center point 43.

The only moments created internally within the tow bar 10 of the presentinvention arise solely from yaw movements between the towing vehicle 15and the towed vehicle 25, which only operatively occur when the towedvehicle 25 is not lined up longitudinally with the towing vehicle 15.The magnitude of the lever arm of those yaw moments is determined by thespacing between the interconnection vertical axis 107 and the hitchingmechanism 35. Due to the simplicity of the structure of the tow bar 10of the present invention, the magnitude of the lever arm of those yawmoments can be minimized by minimizing the spacing between theinterconnection vertical axis 107 and the hitching mechanism 35. Inother words, the structure of the tow bar 10 of the present inventionhas substantially reduced the number of moving parts and has alsosubstantially reduced the various internally-created moments observedfor prior art tow bars.

For most applications, various components of the tow bar 10 of thepresent invention are constructed of strong, high tensile-strengthmaterials such as steel, brass, or other suitable materials. For someapplications, it may be desirable to construct the ball member 41 of lowtensile-strength material, such as teflon for example. In that event,the shaft member 87 includes a circularly-shaped disc 133 rigidlyaffixed to and separating the shaft member 87 into a distal end 135 anda proximal end 137, as shown in FIGS. 7 and 8. In addition, the ballmember 41 comprises a distal portion 139 and a proximal portion 141. Thedistal portion 139 of the ball member 41 has a throughbore 143 with adiameter which is dimensioned to fit snugly about the distal end 135 ofthe shaft member 87. The proximal portion 141 of the ball member 41 hasa partial bore or throughbore 145 with a diameter which is dimensionedto fit snugly about the proximal end 137 of the shaft member 87. Thedistal and proximal portions 139, 141 of the ball member 41, and thelocation and thickness of the disc 133 relative to the distal andproximal ends 135, 137 of the shaft member 87, when assembled as shownin FIG. 7, provide the spherically-shaped ball member 41 as hereinbeforedescribed and as shown in FIG. 5. If desired, a washer 147 around thedistal end 135 of the shaft member 87 may be used to provide a broadersupport base for the shaft member. It is generally unnecessary to bondthe distal and proximal portions 139, 141 of the ball member 41 to theshaft member 87 because assembly of the body member 45 with the ballmember 41 thereinside as hereinbefore described, the ball member 41being assembled as shown in FIG. 7, operatively captures and retains thedesired spherical shape of the ball member 41 without bonding.

It may be desirable to minimize exposure of the ball member 41 to debrisand various other adverse elements of the environment by providing aflexible, corrugated boot to cover the various potential accesses to themain cavity 47.

It may also be desirable to include a mechanism 148 in each towbar arm97, 99 that allows the length of the respective towbar arm 97, 99 to beselectively changed to simplify connecting the tow bar 10 to the towedvehicle 25, wherein each of the towbar arms 95, 97 automatically returnsto a selected towing length by simply driving the towing vehicle 15forward after the tow bar 10 has been connected to the towing vehicle 15and to the towed vehicle 25. Another benefit provided by the mechanisms148 is the ability to shorten the reach of the towbar arms 97, 99 whenthe tow bar 10 has been placed in the stowed configuration 119 on theback of the towing vehicle 15. Examples of such mechanisms 148 aredisclosed in U.S. Pat. No. 5,224,960 issued Jul. 6, 1993 to Lee H.Duncan and in U.S. Pat. No. 5,356,166 issued Oct. 18, 1994 to Merton K.Hahne et al, each of which disclosures are incorporated herein byreference.

In an application of embodiment 10 of the present invention, thehitching mechanism 35 is inserted and secured in the conventionalreceiver hitch 17 of the towing vehicle 15. If the tow bar 10 has beenpreviously secured to the towing vehicle 15 and is in the stowedconfiguration 119, then the tow bar arms 97, 99 are grasped andmaneuvered to disengage the latching mechanism 117, to rotate the bodymember 45 about the ball member 41 to thereby displace the towbar arms97, 99 rearwardly toward the towed vehicle 25, and to secure the towedvehicle connection mechanism 23 to the towed vehicle 25. Of course, anapplication of the tow bar 10 would also involve the proper use ofsafety chains, electrical hookups, etc., as commonly known in the art.

Conversely, if the towed vehicle 25 is to be temporarily disconnectedfrom the towing vehicle 15, the towed vehicle connection mechanism 23 isdisconnected from the towed vehicle 25; the tow bar arms 97, 99 are usedto rotate the body member 45 about the ball member 42 to therebydisplace the towbar arms 97, 99 to a generally upright orientation, andthe latching mechanism 117 is tilted sidewise to engage the latchingmechanism 117 to thereby releasably secure the tow bar 10 in the stowedconfiguration 119 on the back of the towing vehicle 15. If it is desiredto disconnect both the towed vehicle 25 and the tow bar 10 from thetowing vehicle 15, the towed vehicle connection mechanism 23 isdisconnected from the towed vehicle 25 and the hitching mechanism 35 isunsecured and withdrawn from the conventional receiver hitch 17 of thetowing vehicle 15. If it is desired to store the tow bar 10 in thestowed configuration 119, the tow bar 10 is usually returned to thestowed configuration 119 before removing the hitching mechanism 35 fromthe conventional receiver hitch 17 of the towing vehicle 15.

The reference numeral 150 generally refers to a modified embodiment ofthe tow bar for connecting a towed vehicle 25 to a towing vehicle 15 inaccordance with the present invention, as shown in FIGS. 9 through 13.Many of the details of the modified embodiment 150 are substantiallysimilar to those hereinbefore described for embodiment 10 and will notbe reiterated here.

The modified embodiment 150 includes a towing vehicle connectionmechanism 153 for connecting the tow bar 150 to a towing vehicle 15, thetowing vehicle connection mechanism 153, upon insertion and securementin the conventional receiver hitch 17 of the towing vehicle 15operatively defining a fore-to-aft towing vehicle axis 155 that is fixedrelative to the towing vehicle 15 and to the towing vehicle connectionmechanism 153; a towed vehicle connection mechanism 157 for connectingthe tow bar 150 to the towed vehicle 25, the towed vehicle connectionmechanism 157 operatively defining a horizontal transversely-orientedtowed vehicle axis 159 that is fixed relative to the towed vehicle 25and to the towed vehicle connection mechanism 157; and aninterconnecting mechanism 161 connecting the towing vehicle connectionmechanism 153 to the towed vehicle connection mechanism 157.

The modified embodiment 150 of the present invention includes a bodymember 163 having a first body portion 165 with a rearwardly-facing,partially hemispherically-shaped first cavity 167 and having a radius ofcurvature, which is slightly greater than the radius of a ball member169 having a ball member center point 170, and a center of curvature171; a second body portion 173 with a forwardly-facing, partiallyhemispherically-shaped second cavity 175 having a radius of curvature,which is identical to the radius of curvature of the first cavity 167 ofthe first body portion 165, and a center of curvature 177; and a thirdbody portion 179 having a forwardly-facing, partiallyhemispherically-shaped third cavity 181 having a radius of curvature,which is identical to the radius of curvature of the second cavity 175of the second body portion 173, and a center of curvature 183. For someapplications, it may be desirable that the second and third bodyportions 173, 179 have a unitary construction, i.e., constructed from asingle piece of material.

The interconnecting mechanism 161 also includes fastening means 185,such as a plurality of cap screws 185 as shown in FIG. 10. Assembly ofthe first body portion 165, the second body portion 173, and the thirdbody portion 179 with the fastening means 185 forms a main cavity 187having a main cavity center point 189, sometimes referred to herein asthe interconnection central point 191, to rotatively capture the ballmember 169 therein, wherein the center of curvature 171 of the firstcavity 167 of the first body portion 165, the center of curvature 177 ofthe second cavity 175 of the second body portion 173, the center ofcurvature 183 of the third cavity 181 of the third body portion 179, andthe ball member center point 170 all coincide with the interconnectioncentral point 191 to rotatively capture the ball member 169 therein.Preferably, the second body portion 173 and the third body portion 179abut the first body portion 165 along a plane 201 that passes throughthe interconnection central point 191.

The interconnecting mechanism 161 also includes a slot 203, having aslot width 205, and a shaft member 207, having a forward end 209 and arearward end 211. The slot 203 is cooperatively formed between thesecond body portion 173 and the third body portion 179 during assemblyof the body member 163. The shaft member 207 has a diameter that isslightly smaller than the slot width 205. The forward end 209 of theshaft member 207 is affixed to the ball member 169 and the rearward end211 of the shaft member 207 extends rearwardly from the ball member 169through the slot 203.

The interconnecting mechanism 161 also includes a towbar arm connector221 affixed to the rearward end 211 of the shaft member 207, and atleast one, preferably two, towbar arms 223, 225. Each towbar arm 223,225 has a forward end 227 and a rear end 229. The forward ends 227 ofthe towbar arms 223, 225 are not spaced apart from each other and areindividually movably connected to the towbar arm connector 221 to pivotabout an interconnection vertical axis 231 provided by a pin 233 througha vertically-oriented throughbore 235 in the towbar arm connector 221,as shown in FIGS. 10 and 11, or other suitable arrangement.

The interconnecting mechanism 161 also includes a latching mechanism 241which is structured and configured to secure the interconnectingmechanism 161 in a stowed configuration 243. The latching mechanism 241may include the shaft member 207 serving as a first latching device 245with the latching mechanism 241 also including a second latching device247 affixed to the body member 163. The second latching mechanism 247can be described as an enlargement of the width of slot 203 near anupward end thereof, as shown in FIG. 10, in order to permit the firstlatching device 245 to appropriately engage the second latching device247.

The latching mechanism 241 is structured and configured wherein the ballmember 169 can be selectively rotated within the body member 163 todisplace the shaft member 207 along the slot 203 to thereby dispose theshaft member 207 in a generally upright orientation. Then, by tiltingthe shaft member 207 to the right or left, the first latching device 245engages the second latching device 247 thereby releasably securing theinterconnecting mechanism 161 in the stowed configuration 243 on theback of the towing vehicle 15.

Again, for some applications, it may be desirable to construct the ballmember 169 of low tensile-strength material, such as teflon for example.In that event, the shaft member 207 includes a circularly-shaped disc263 rigidly affixed to and separating the shaft member 207 into a distalend 265 and a proximal end 267, as shown in FIG. 12. In addition, theball member 169 comprises a distal portion 269 and a proximal portion271. The distal portion 269 of the ball member 169 has a throughbore 273with a diameter which is dimensioned to fit snugly about the distal end265 of the shaft member 207. The proximal portion 271 of the ball member169 has a partial bore or throughbore 275 with a diameter which isdimensioned to fit snugly about the proximal end 267 of the shaft member207. The distal and proximal portions 269, 271 of the ball member 169,and the location and thickness of the disc 263 relative to the distaland proximal ends 265, 267 of the shaft member 207, when assembledprovide the spherically-shaped ball member 169 as hereinbeforedescribed. It is generally unnecessary to bond the distal and proximalportions 269, 271 of the ball member 169 to the shaft member 207 becauseassembly of the body member 163 with the ball member 169 thereinside, ashereinbefore described, captures and retains the desired spherical shapeof the ball member 169 without bonding.

An application of the modified embodiment 150 of the present inventionis substantially similar to the above described description for anapplication of embodiment 10 of the present invention with an exceptionbeing that converting the modified tow bar 150 to the stowedconfiguration 243 causes the ball member 169 to be selectively rotatedwithin the body member 163, as opposed to rotating the body member 45about the ball member 41 as described for embodiment 10.

It is to be understood that while certain forms of the present inventionhave been illustrated and described herein, it is not to be limited tothe specific forms or arrangement of parts described and shown.

1. A tow bar for connecting a towed vehicle to a towing vehicle, the towbar comprising: (a) a towing vehicle connection mechanism connected tothe towing vehicle, the towing vehicle connection mechanism defining afore-to-aft oriented towing vehicle axis that is operatively fixedrelative to the towing vehicle and to the towing vehicle connectionmechanism; (b) a towed vehicle connection mechanism connected to thetowed vehicle, the towed vehicle connection mechanism defining ahorizontal transversely-oriented towed vehicle axis that is operativelyfixed relative to the towed vehicle and to the towed vehicle connectionmechanism; and (c) an interconnecting mechanism connecting the towingvehicle connection mechanism to the towed vehicle connection mechanism,the interconnecting mechanism defining: (1) an interconnection centralpoint, and (2) an interconnection vertical axis spaced rearwardly fromthe interconnection central point; and wherein the interconnectingmechanism includes: (3) a spherically-shaped ball member having a radiusand a ball member center point; and (4) a body member having a maincavity with a main cavity center point and a radius of curvature, whichis slightly greater than the radius of the ball member, and (5) whereinthe ball member is rotatively captured within the body member with theball member center point and the main cavity center point coincidingwith the interconnection central point; and wherein the body memberincludes: (A) a first body portion having a rearwardly-facing, partiallyhemispherically-shaped first cavity with a radius of curvature, which isslightly greater than the radius of the ball member, and a center ofcurvature; (B) a second body portion having a forwardly-facing,partially hemispherically-shaped second cavity with a radius ofcurvature, which is identical to the radius of curvature of the firstcavity of the first body portion, and a center of curvature; (C) a thirdbody portion having a forwardly-facing, partially hemispherically-shapedthird cavity with a radius of curvature, which is identical to theradius of curvature of the second cavity of the second body portion, anda center of curvature; and (D) fastening means; and (E) wherein assemblyof the first body portion, the second body portion, the third bodyportion and the ball member with the fastening means forms the maincavity wherein the center of curvature of the first cavity of the firstbody portion, the center of curvature of the second cavity of the secondbody portion, the center of curvature of the third cavity of the thirdbody portion and the ball member center point all coincide with the maincavity center point, rotatively capturing the ball member therein; and(d) wherein the interconnecting mechanism is configured and structuredto accommodate substantially all pitch and roll movements, including anyand all combinations thereof, between the towing vehicle axis and thetowed vehicle axis, at and about the interconnection central point; andwherein the interconnecting mechanism is further configured andstructured to accommodate substantially all yaw movements, between thetowing vehicle axis and the towed vehicle axis, at and about theinterconnection vertical axis.
 2. The tow bar as described in claim 1wherein, wherein the second and third body portions are of unitaryconstruction.
 3. The tow bar as described in claim 1 wherein, afterassembly of the body member with the fastening means, the second andthird body portions abut the first body portion along a plane thatpasses through the interconnection central point.
 4. The tow bar asdescribed in claim 1 wherein the interconnecting mechanism furtherincludes: (a) a slot having a slot width, the slot being cooperativelyformed between the second and third body portions by assembly of thebody member; and (b) a shaft member having a forward end, a rearward endand a diameter, which is slightly smaller than the slot width, theforward end thereof being affixed to the ball member and the rearwardend thereof extending rearwardly through the slot.
 5. The tow bar asdescribed in claim 4, wherein (a) the shaft member includes atransversely-oriented disc which separates the shaft member into aproximal end and a distal end; and (b) the ball member comprises (1) aproximal portion having a partial bore or throughbore having a diameterdimensioned to fit snugly around the proximal end of the shaft member,and (2) a distal portion having a throughbore having a diameterdimensioned to fit snugly around the distal end of the shaft member; and(c) wherein the spherical shape of the ball member is provided byassembly of the proximal portion of the ball member onto the proximalend of the shaft member and by assembly of the distal portion of theball member onto the proximal end of the shaft member with thetransversely-oriented disc sandwiched between the proximal and distalportions of the ball member.
 6. The tow bar as described in claim 4wherein the interconnecting mechanism further includes: (a) a towbar armconnector affixed to the shaft member; and (b) at least one towbar armhaving a forward end and a rear end, the forward end thereof beingpivotally connected to the towbar arm connector to pivot about theinterconnection vertical axis and the rear end thereof being connectedto the towed vehicle connection mechanism.
 7. The tow bar as describedin claim 6 wherein the at least one towbar arm includes two towbar arms,each having a forward end and a rear end, wherein the rear ends thereofare operatively spaced apart and connected to the towed vehicleconnection mechanism and wherein the forward ends thereof are not spacedapart and are pivotally connected to the towbar arm connector to pivotabout the interconnection vertical axis.
 8. The tow bar as described inclaim 7, wherein the forward ends of the two towbar arms can pivotseparately or in unison about the interconnection vertical axis.
 9. Thetow bar as described in claim 4, further comprising: (a) a latchingmechanism structured and configured to secure the interconnectingmechanism in a stowed configuration, the latching mechanism including:(1) a first latching device affixed to the ball member, and (2) a secondlatching device affixed to the body member; and (b) wherein, as the ballmember is rotated within the body member to displace the shaft member toa generally upright orientation, the first latching device inconjunction with the second latching device releasably secures theinterconnecting mechanism in the stowed configuration.
 10. A tow bar forconnecting a towed vehicle to a towing vehicle, the tow bar comprising:(a) a towing vehicle connection mechanism connected to the towingvehicle, the towing vehicle connection mechanism (1) including ahitching mechanism structured and configured to be received by aconventional receiver hitch of the towing vehicle, and (2) defining afore-to-aft oriented towing vehicle axis that is operatively fixedrelative to the towing vehicle and to the towing vehicle connectionmechanism; (b) a towed vehicle connection mechanism connected to thetowed vehicle, the towed vehicle connection mechanism (1) including atleast one bracket attached to the towed vehicle, and (2) defining ahorizontal transversely-oriented towed vehicle axis that is operativelyfixed relative to the towed vehicle and to the towed vehicle connectionmechanism; (c) an interconnecting mechanism connecting the towingvehicle connection mechanism to the towed vehicle connection mechanism,the interconnecting mechanism defining an interconnection central point,defining an interconnection vertical axis spaced rearwardly from theinterconnection central point, and including: (1) a spherically-shapedball member having a radius and a ball member center point, (2) a bodymember having a main cavity with a main cavity center point and a radiusof curvature, which is slightly greater than the radius of the ballmember, the body member further including: (A) a first body portionhaving a rearwardly-facing, partially hemispherically-shaped firstcavity with a radius of curvature, which is slightly greater than theradius of the ball member, and a center of curvature, (B) a second bodyportion with a forwardly-facing, partially hemispherically-shaped secondcavity with a radius of curvature, which is identical to the radius ofcurvature of the first cavity of the first body portion, and a center ofcurvature, and (C) a third body portion with a forwardly-facing,partially hemispherically-shaped third cavity with a radius ofcurvature, which is identical to the radius of curvature of the secondcavity of the second body portion, and a center of curvature, and (D)fastening means, and (E) wherein assembly of the first body portion, thesecond body portion, the third body portion and the ball member with thefastening means forms the main cavity of the body member wherein thecenter of curvature of the first cavity of the first body portion, thecenter of curvature of the second cavity of the second body portion, thecenter of curvature of the third cavity of the third body portion, andthe ball member center point all coincide with the main cavity centerpoint, rotatively capturing the ball member therein; and wherein thesecond and third body portions abut the first body portion along a planethat passes through the main cavity center point, (3) a slot having aslot width, the slot being cooperatively formed between the second andthird body portions by assembly of the body member, (4) a shaft memberhaving a forward end, a rearward end and a diameter which is slightlysmaller that the slot width, the forward end thereof being affixed tothe ball member, and the rearward end thereof extending rearwardlythrough the slot, (5) a towbar arm connector affixed to the shaftmember, and (6) a pair of towbar arms, each having a forward end and arear end, wherein the rear ends thereof are operatively spaced apart andconnected to the towed vehicle connection mechanism, and the forwardends thereof are not spaced apart and are movably connected to thetowbar arm connector to pivot about the interconnection vertical axis;and (d) a latching mechanism structured and configured to secure theinterconnecting mechanism in a stowed configuration, the latchingmechanism including: (1) a first latching device affixed to the ballmember, and (2) a second latching device affixed to the body member, and(3) wherein, as the ball member is rotated within the body member todisplace the shaft member along the slot to thereby dispose the shaftmember in a generally upright orientation, the first latching device inconjunction with the second latching device releasably secures theinterconnecting mechanism in the stowed configuration; and (e) whereinthe interconnecting mechanism is configured and structured toaccommodate substantially all pitch and roll movements including any andall combinations thereof, between the towing vehicle axis and the towedvehicle axis, at and about the interconnection central point; andwherein the interconnecting mechanism is further configured andstructured to accommodate substantially all yaw movements, between thetowing vehicle axis and the towed vehicle axis, at and about theinterconnection vertical axis.